Thermo-electrical system.



No. 880,272. PATENTE D FEB. 25, 1908. W. H. BRISTOL.

THERMO ELECTRICAL SYSTEM. APPLIOATIQN mum NOV. 11, 1967.

UNITED STATES PATENT OFFICE.

TIIERMO-ELECTRICAL SYSTEM.

Application filed Novembcrll. 1907. Serial No. 4011662.

'1 b all whom may (OH-('(H'TI-I Be it known that l, W1i.i.n\M.ll.Bmsron, a citizen of the United States, and a resident of New York, inthe county of New York and State of New York, have invented certain newand usciul lmprovcments m 'lhermo- Electrical Systems, of which thefollowing is a specification.

My invention relates to indicating and recording systems, andparticularly to a system affected by temperature changes; and it has forits object a system of this character adapt cd to respond to a suddenchange of temperature, but not to a constant temperature or to a gradualchange of temperature. I attain this object in the system set forth inthe specification and illustratedin the accompanying drawings in which--Figure l is a diagrannnatic view illustrating the system. Fig. 2 is asimilar view illustrating some additionalfeatures. Fig. 3 is across-sectional view on an enlarged scale of the member used inconnection with the system illustrated in Fig. 2.

Similar characters of reference designate corresponding parts throughoutthe several views.

Referring to Fig. l of the drawings,..10 indicates a thermo-clectriccouple comprising two dissimilar and suitable elements 11 and 12, joinedat the hot end 13 and attached at the cold end 14 to the leads l5 andHirespectivcl "lhe hot end 13 is left barefor is protected by somethermally conductive material as a mixture of powdered carboruiulum anda solution of sodium silicate, as disclosed in my prior )atent No.798,260 of August 29th, 1905. he cold end 1:4, however, must in allcases be thermally insulated to a certain degree, as by a winding ofinsulating tape, by gutta-percha or porcelain tube, or other similarmaterial 17. The hot end 13 may also be of reduced cross-section, asshown, so

as to more quickly assume the temperature of the medium to which it isexposed, as set forth in my prior patent No. 764,175 of July 5th, 1904.When required to respond to very small differences of temperature, anumber of such couples (not shown) may be connected in series.

- ln Figs. 2 and Bthe couple 10 is shown in-' serted into a well 18; andin this event, the hot'end 13 is preferably arranged to touch the innerwall of said well as shown in Fig. 3. The cold end 14 is laced in close)roximity to the said hot end; )ut is arrange however, so asSpecification of Letters Patent.

the bell 25.

OF NEW YORK, N. Y.

Patented Feb. 25, 1908.

not to touch the wall of the. well 18, being thermally insulated as inthe case of the couple shown in Fig. 1. 'An insulating casing or tube 19is placed about the couple l0, and about the casing is wound a heatingcoil 20 of suitable resistance wire.

In both forms of Couple, however, it is essential that the hot and coldends of the couple be so located, that, :when in action, they shall beacted upon by the same temperature existing in the medium.

As shown in Fig. l the leads 15, 16 connect to electrical apparatus, asthe relay 2]. In .Fig. 2 1 have shown a sensitive recorder 22, such asthe smoked chart recorder disclosed in my prior patent No. 813,689 ofFebruary 27th, 1906 in series in the lead 16, the leads connecting alsoto a relay 2]... 1f simply an indication be desired the recording device22 maybe replaced by the usual indicat- X I a mg milh-voltmeter orm1ll1-ammeter (not,

alarm or signal circuit 23 comprising a source of electrical energy asthe battery 24 and a suitable indicating device, signal or alarm as Thearm 27 of the relay is balanced so as to be responsive to a currentflowing in either direction, and will close the local circuit 23 ineither event.

A test circuit 28, Fig. .2 is provided and comprises a source ofelectrical energy as the feeders 29, lamp 30, switch 31 and the heatingcoil 20 previously described. Byclosing switch 31' a current is sentthrough the coil 20 (as indicated b the lamp 30), and causes the same toheat t 1c cou do 10.

The o cration of tlie stem is as follows: It iswe'll kn .)wn that iftlie hot and cold end of a thermo-electrie couple are at the sametemperature, or if. both ends are simultaneously exposed to the sametemperature, no thermoelectric current isprQduc'ed, asithe' setting upof an electro-motive'force depends upon the existence of a diflercnce oftemperature between the two ends. If now,',

iorary electro-motivc' force wil be set up.

he couple therefore, if taken from one tern perature after both ends areat the same temperature, and suddenly placed in a medium having adill'erent temperature, will respond, even though both of the ends arein the medium and acted upon by the same temperature, since there is alag in the case of one end in assuming the new temperature. ll bothends, after an interval, then arrive at the same temperature, the coupleno longer responds, and a gradual change will not produce anyappreciable ell ect since the dill'erenee between the two ends is notsullicient. A sudden change however, will pro duce an appreciableell'ect' due to the lag of one end in assuming the new temperature. Thissmall electro-motive force set. up is suf ficient to operate therecording device 22, relay 21, etc, which relay in turn controls thelocal and more powerful circuit 23 adapted to operate various devices orsignals. The test circuit 28 is employed to produce a. sudden change oftemperature at the couple, and

thereby determine whether the operating circuit is intact. The recorder22 will act as a check upon the testing as it will record the eXact timewhen such test was made.

Numerous applications of this system will suggest themselves',.onc inparticular will be mentioncdthat of detecting, on board of a shi thepresence of icebergs. If-thc couple 10 e inserted in the well 18, whichcan be arranged in the plates of the ship so as to be under water, thecouple will therefore be con. 'tinuously ex )osed to substantially thetemperature of t to water. 7

So long as the tem )erature is constant, or, changing only gradually, noappreciable change in the relativetemperature of the ends of the coupleoccurs. However, as soon as the ship arrives in the neighborhood of aniceber the temperature suddenly and appreciably drops. This will causethe coup e 10 to make a record, close the relay and thereby the alarmcircuit, and give the necessary alarm. At every watch the. test cir-/cuit may be closed to determine if operating circuit is intact. I claim:

1. A thermo-electric couple, adapted to set up a temporaryelectro-Inotive force when a sudden change of temperature occurs at. theends, both ends being inithe same medium, but so arrangedthat oneassumes the sald temperaturemore quickly than the other.

2; thermo-electric couple, having its ends 1n close proximityand adaptedto set up a temporary electro-motive force when a sudden change oftemperature occurs at said ends, one end assuming the said temperaturemore quickly'than the other.

3. A thermo-electric couple, provided with means adapted to cause thesame to set up a temporary electro-motive force, and only when both endsof said couple are simultaneously exposed to an appreciable and suddenchange of temperature.

4. A thermo-clectric couple, both ends of which are adapted to besimultaneously exposed to an appreciable and'sudden change oftemperature, butone of which is adapted to assume. said temperature morerapidly than the other.

A tltermo-electric couple, both ends of which are adapted to besimultaneously exposed to an appreciable and sudden change oltemperature, but one of which is thermally insulated, whereby the otherend assumes said temperature more rapidly than said thermally insulatedend.

(3. .In an electrical system: electrical apparatus; and means inconnection therewith adapted to all'ect said electrical apparatus whenacted upon by a sudden change of temperature, but substantially inactivewith respect to said electrical apparatus when acted upon by a constanttemperature and by a gradual change of temperature.

7. In an electrical indicating system: an indicating device; and meansin connection therewith adapted to a'll'ect said indicating device whenacted upon by a sudden change of temperature, but substantially inactivewith respect to said indicating device when acted upon by a constanttemperature and by a gradual change of temperature.

8. In an electrical system: electrical ap-' paratus; and means inconnection therewith adapted to generate a temporary current ofelectricity when acted upon by a sudden change of temperature, butgenerating no appreciable current when acted upon by a. constanttemperature and by a gradual change of temperature.

9. In an electrical indicatingsystem: an indicating device; and means inconnection therewith adapted to generate a temporary current ofelectricity when acted uponby a sudden change of temperature, butgenerarc acted upon by a sudden change of temperature, but generating noappreciable current when acted upon by a constant temperature and by agradual change of temperature.

11. In an'electrical indicating system: an indicating device; and ath'ermo-electrie couple in series therewith adapted to generate atemporary current of electricity when both ends are simultaneously actedupon by a sudden change of temperature, but generating no appreciablecurrent when the same are acted upon by a constant temperature and by agradual change of temperature.

12. In an electrical indicating system: an indicating device; and athermo-electric couple in, series therewith, one of whose ends isthermally insulated to' such a degree that the said couple whenactedupon by a sudden change of temperature will generate a temporarytherino-elcctric current, but when acted upon by a constant temperatureand by a gradual change of temperature will not set up an appreciablethcrnm-electric current.

13. In an electrical indicating and recording system: an indicating,device; means in connection therewith adapted to affect said indicatingdevice when acted upon by a suddenchange of tem )erature, but inactivewith respect to said indicating device when acted 'upon by a constanttemperature and by a gradual change of temperature; and means to recordthe el'l'ect of said means.

14. In an electrical system, a relay, and a local alarm circuitcontrolled there y; and means in connection with said relay adapted toafi'ect the same when acted upon by a sudden change of temperature, butinactive with respect to said relay when acted upon by a constanttemperature and by a gradual change of tem )erature.

15. In an electrical system: a relay and a local alarm circuitcontrolled thereby; and a thermo-electric couple in series therewithadapted to all'ect the same when acted upon by a sudden change oftemperature, but inactive thereto when acted upon by a constanttemperature and by a gradual change of tem erature.

16. 11 an electrical system: a relay and a local alarm circuitcontrolled thereby; and a thermo-electric couple series therewith, oneof whose ends is thermally insulated to I such a degree,

that the said couple when acted u on by a sudden change of temperaturewill generate a temporary thermo-electric current, but when acted uponby a constant temperature and by a gradual chan e of temperature willnot set up an appreciab e thergno-electric current.

17. In an electrical system: a relay and a local alarm circuitcontrolled thereby; a thermo-electric couple in series therewith, one ofwhose ends is thermally insulated to such a degree, that the said couplewhen acted upon by a sudden change of temperature willgencrate atemporary thermo-electric current, but when acted upon by a constanttempera ture arid by a gradual change of temperature will not set up anappreciable thermo-electric current; and means to record saidthermo-electric current.

18. In a system of the character specified:

'a well adapted to be subjected to temperafrom; and aheating coil aboutsaid couple for the purpose specified.

Signed at New York in the county of New York and State of New York this8th day of November A. D. 1907.

' WILLIAM H. BRISTOL.

Witnesses:

GEORGE A. MINASIAN, FREDK F. SeHUE'rz.

